Method of making closure caps



' May 25, 1937.

E. M. ENKUR METHOD OF MAKING CLOSURE CAPS Original Filed March 15, 1953 5 Shets-Sheet 1 May 25, 1937. E. M. ENKUR 2,081,804

METHOD OF MAKING CLOSURE CAPS Original Filed March 15, 1955 5 Sheets-Sheet 2 zyrg'zz. Z9 7 159 6 i 1 i ii May 25, 1937.

I METHOD OF MAKING CLOSURE CAPS kl I a m m m E. M; ENKUR 2,081,804

Original Filed March 15, 1933 5 Sheets-Sheet 3 May 25, 1937. E. M. ENKUR METHOD OF MAKING CLOSURE CAPS Original Filed March 15, 1953 5 Sheets-Sheet 4 aaaaaae iaa EZQ , i y, l1

E. M. ENKUR 2,081,804

METHOD OF MAKING CLOSURE CAPS Original Filed March 15, 1953 5 Sheets-Sheet 5 method of making lug type closure caps.

Patented May 25, 1937 UNITED STATES METHOD OF MAKING CLOSURE CAPS Edward M. Enkur, Baltimore, Md., assignor, to Crown Cork & Seal Company, Inc., Baltimore,

Md, a corporation of New York Application March 15,

1933, Serial No. 660,927

Renewed October 27, 1936 19 Claims.

This invention relates to a new and improved More particularly, it relates to a method which may be used in making lug caps of the type disclosed in the co-pending application of Kramer and Enkur, Serial No. 657,734, filed February 20, 1933.

Lug caps made in accordance with the present method present many advantages and improvements over caps of the prior art, as fully pointed out in the aforesaid application.

In the first place, such caps are provided with inwardly projecting locking lugs disposed interiorly of the cap skirt, concealed from view thereby, and located on an inwardly rolled, beaded edge. The lower end of the cap skirt terminates in a uniformly rounded edge, which presents a smooth, undistorted surface, and a'greatly improved appearance. No indentations or other disfiguring marks appear in the cap skirt adjacent the lugs. The cross sectional curve of the inturned edge of the cap skirt is not sufliciently sharp at any point to injure the lacquer coating conventionally applied to the cap making material before the cap is made.

Furthermore, in caps of the type referred to in the aforesaid application, a reinforced lug having a rounded thread engaging surface is provided.

It is an object of the present invention to provide a method of making caps of the concealed lug type which is simple, inexpensive, and rapid. It is a further object of the invention to provide a method which will not unduly stretch or tear the material of the cap during the beading and lug forming operation.

It is a further object of the invention to provide a method of making a lug cap of the type referred to without marring or otherwise injuring a lacquer coating which may have been applied to the cap making material.

It is a further object of the invention to provide a method of making a closure cap having an internal, concealed lug of predetermined shape (r contour.

By following the method of the present invention, a lug may be formed on the inwardly curled head of a cap skirt, and the lug may be given certain desirable characteristics with res cct to length and depth. Furthermore, it may be rounded on a predetermined arcuate curve and thus present a desirable and improved thread engaging surface.

According to the present method, the free edge of the skirt of a cup shaped cap blank is first given an inward curl to form a partial bead or into the interior of the cap skirt, substantially in position to engage the conventional thread on a receptacle neck. If desirable, the cap may be given a final finishing step, and all points on the lower edge of the cap skirt horizontally aligned, so that the cap as a whole presents a uniform external appearance.

In the accompanying drawings, suitable ap-' paratus for performing each of the several steps of the present method is disclosed. The apparatus, of course, is not limited to the specific die and press structures shown, for any similar mechanical devices may be used.

In the drawings,

Figure 1 is a vertical axial sectional view of a cup-shaped blank, which may be made by a conventional drawing operation, and which is suitable for use in the method of the present invention;

Figure 2 is a similar view showing the blank after a preliminary first step in the method has been performed;

Figure 3 is a similar view of the blank after the first bead forming operation has been performed;

Figure 4 is a similar view of the blank after the next step in the method has been completed;

Figure 5 is a bottom plan view of the blank in the condition shown in Figure 4;

Figure 6 is a vertical axial sectional view of the blank after the next step in the method has been completed;

Figure 7 is a similar view of the finished cap;

Figure 8 is a bottom plan view of the finished Figure 9 is an elevational view of the same, showingv the smooth exterior surface of the completed cap; 7

Figure 10 is a fragmentary plan View of the completed cap, with a portion of the topbroken away to reveal the structure of one of the lugs;

Figure 11 is an enlarged fragmentary view, similar to the blank disclosed in Figure 2;

Figure 12 is a similar view and. shows the blank in the stage represented by Figure 3;

Figure 13 is a similar view and corresponds to Figure 4;

Figure 14 is an enlarged fragmentary showing, similar to Figure 6, but taken through the bead portion of the cap skirt;

Figure 15 corresponds to Figure 14, but shows a section of the blank taken through the lug portion;

Figure 16 is an enlarged fragmentary sectional view of the completed cap, taken through the bead;

Figure 17 is a similar view of the completed cap taken on a section through one of the lugs;

Figure 18 is a similar view showing the cap on a receptacle;

Figure 19 is a vertical sectional view of an apparatus which may be conveniently employed for performing the first, or preliminary, step of the method, represented by Figure 2;

Figure 20 is a similar view, with certain parts omitted, showing the first curling die, which may perform the step represented by Figure 3;

Figure 21 is a vertical sectional view through an apparatus which is adapted to perform the third step in the method, disclosed in Figures 4 and 13;

Figure --22 is a horizontal sectional view, taken on line 2222 of Figure 21;

Figure 23 is a horizontal sectional view taken on line 2323 of Figure 21;

Figure 24 is a vertical sectional View, taken on line 2424 of Figure 25, of an apparatus adapted to perform the fourth step in the method, repre sented by Figures 6, 14 and 15;

Figure 25 is a bottom plan view of the die disclosed in Figure 24;

Figure 26 is a view similar to Figure 24 buttaken on a difierent section, represented by line 26-46 of Figure 25; and

Figure 27 is a vertical section through an apparatus which may be used to perform a final and finishing step in the method.

Referring to the drawings, a cup-shaped blank having a top 25 and a cylindrical flange, or skirt, 26, is disclosed in Figure 1, and this blank may be made in a conventional drawing operation from a sheet of metal usually having a lacquer coating on its lower surface, or in some cases on both surfaces. In the several forming operations, which convert the shell"or-blank of Figure 1 into the completed cap of Figure 7, the blank is preferably positioned up-side-down, as shown, and is moved step by step from one press to the next. The general plan of the machine forms no part of the invention of the present application, and consequently, the specific means for simultaneously moving a plurality of blanks in step by step motion to the various stations is not disclosed.

The blank of Figure 1 has a substantially cylindrical skirt 26 terminating in a raw edge 21,

which is slightly outwardly flared, as indicated at 28, when the blank comes from the drawing dies. Since it is necessary in the present method to curl the end portion of the skirt inwardly, it has been found expedient to first start the curl by turning the free edge 2'! from its outwardly flared position to a slightly inwardly bent position. This first step, in some cases, may be dispensed with, but it has been found desirable with the usual run of blanks. The result of the preliminary edge bending operation is disclosed in Figures 2 and 11, and it will be noted that the cross-sectional shapev of the skirt edge has been changed just enough to facilitate the next curling operation, and is now disposed slightly in wardly at 29.

tively short radius;

The second step in the method comprises giving the skirt a reinforce, in the nature of an inwardly curled edge or a substantially beaded or wired edge, as shown in Figures 3 and 12. The free edge 21 of the skirt is rolled inwardly and upwardly into a substantially semi-circular (or greater) bead 3|]. Thus, the skirt 26 is provided with a strengthened, reinforced edge 30, entirely around its perimeter.

The next step in the method, as disclosed in Figures 4, 5 and 13, comprises bending outwardly, certain circumferentially spaced portions 3i of the wire 30, and forming each portion into a predetermined shape or contour, suitable for ultimate engagement with the thread on a receptacle neck. Preferably the outwardly bent or otherwise shaped portions 31 have their outer surfaces disposed upon arcuate curves of rela- The reinforced edge is such that when the wire is bent to any particular form, it will tend to maintain that former shape during the subsequent steps of the method. Consequently, the exterior surface 32 of each of the portions 3| may be given initially substantially the shape and curve which is desired on the thread engaging surface of the finished lug. After the step disclosed in Figures 4 and 5 has been performed, the beaded edge of the blank between the portions 3| is given a further curl by a die such as that disclosed in Figures 24 to 26, inclusivefand this further curling or beading of the intermediate portions results in drawing the portions 3| from their outwardly bent or otherwise shaped position, inwardly with respect to the capskirt to substantially the position of Figure 6. This movement of the portions 3| is in the nature of a bodily displacement, without substantial distortion of the lug forming portions, and each swings or turns about an axis parallel to the cap top, from the position of Figure 4 to that of Figure 6. As stated, this bodily displacement of the lug forming portions 3| is accomplished without applying any force directly thereto, but results from drawing forces transmitted to those portions through the material of the bead, from the curling pressure appliedto the intermediate sections of the bead.

Furthermore, during the movement of the lug formingportions 3| from their original outwardly bent position,, to the inwardly disposed position, their form isnot substantially altered, because they merely follow the rolling or curling movement imparted to the intermediate bead portions, and swing inwardly without distortion.

As a result of my discovery that the material of a cap skirt will act in this manner when a curling pressure is applied to spaced portions thereof, I am able to impress any desired thread engaging contour or surface to the lug forming portions 32, and this shape or contour will appear in the lugs of the ultimate cap.

As a final finishing step, in some cases it is found desirable to horizontally align all points on the lower edge of the cap skirt, and this may be done by simply curling the bead portions a little more, and pushing the lugs 33, Figure 6, toward the top of the cap, as disclosed in Figure 7.

The change in the form of the edge of the cap skirt resulting from the fourth step in the method is clearly indicated by a comparison of Figures 12 and 13, on the one hand, with Figures Hand 15, on the other hand. When the partial bead or wired edge of Figures 12 and 13 is given a further curl, it assumes the form substantially as shown in Figure 14. The wire 30 is rolled inwardly, and the free edge 21 is disposed inside of a slightly enlarged bead or coil 35. At the spaced, lug forming portions 3|, where the wire has been bent outwardly, as disclosed in Figure 13, the edge is not curled up in the same manner as adjacent portions, but is merely bodily swung inwardly to the position of Figure 15. The predetermined arcuate curve 32 which was imparted to the outer surface of the wire, now lies inside of the cap skirt in position to contact a receptacle thread. The original curl 30 at the lug portions constitutes a reinforce for the lug, and is joined to the cap skirt by a fiat curved portion 36.

After the final step has been completed, the bead portions of the cap and the lug portions assume substantially the position shown in Figures 16 and 17. All portions of the rolled edge of the.

cap skirt have been horizontally aligned, so that the skirt presents a smooth exterior surface, and a uniform lower edge.

Figures 19 to 27show various forms of dies and associated apparatus, adapted to perform the several steps discussed above. As previously stated, these dies may conveniently be assembled in an appropriate automatic machine, so that cap blanks will be fed in step by step movement from one station to the next.

In the apparatus of Figure 19, a stationary base block 50 is provided with a socket in which is mounted a nest supported by a spring-pressed plunger 52. Above the block, a die forming assembly is hung from a cross-head 54. This assembly comprises a cylindrical die 55 fixedly secured to the cross-head and having a forming groove 56 on its bottom face. Within a central bore in the die 55 is a rod 51 normally projected downwardly by compression spring 58. Upon the lower end of the rod is a clamping pad 59 which, as the parts descend, first comes in contact with the interior surface of the top of the cap blank, to hold the blank in position. Surrounding the rod 51, in spaced relation thereto, and within the die member 55, is a depending sleeve 69 having its lower end provided with a rounded cam surface 6|. Surrounding the sleeve 60, and also within the die 55, is an expanding collet 62 made up of a plurality of spring fingers integral with a ring 63. Each of the fingers adjacent its lower end'is provided with an inner cam surface 64 positioned to be engaged by the surface 6| of sleeve 60. Each finger terminates at its lower end in an outwardly projecting head 65. A compression spring 66 is disposed between a shoulder on fingersGZ and a flange on the upper end of sleeve 60 to maintain each head 65 in contact with the upper surface of pad 59.

When the die assembly descends the clamping pad 59 moves inside of the cap blank, and the pad holds the blank upon the nest. Because the spring 53 below the nest is of lighter tension than springs 66 .and 58, the continued movement of the pad 59 depresses the nest and blank into the socket in block 50. Further downward movement,after the nest reaches the bottom of the socket, is permitted by the lost motion between rod 51 and cross-head 54, and by compression of the spring 58. Such downward movement results in relative movement between the sleeve 89 and the fingers 62, and a consequent camming action between their cam surfaces. Thus, each finger is spread outwardly and the heads move into position to support the inner wall of the cap skirt. Immediately thereafter, the bottom surface of the die 55 comes into contact with the edge 35 of the blank flange and the groove 56 gives it a slight inward bend or nip. The fingers 62 are useful in assuring that the bend is confined to an area closely adjacent the. edge of the flange.

When the cross-head 54 is raised, the movement of the parts is substantially the reverse of that described above, and the blank is raised to a level substantially equal to the top of the block 50 from which position it may be moved to the next station.

Instead of using a spring pressed nest 5|, as disclosed in Figure 19, a one-piece stationary nest 5|, disclosed in Figures 20, 21 and 27 may be used to advantage. With a two-part assembly such-as is disclosed in Figure 19, a minute groove is necessarily present at the juncture between the movable member 5| and the block 50, and this groove results in the formation of a slight rib, or other disfiguring mark, on the exterior of the blank. When a one-piece construction is used, this difficulty is obviated.

As a substitute for the spring pressed blank ejecting means of Figure 19, the nest may be provided with a central bore to which is connected a compressed air pipe 5|". Thus, after the particular operation has been performed, a blast of air may be utilized to eject the blank. If desired, the nest maybe movable from station to station until all operations have been performed, and, after the last one, the blast of air will be effective to eject the cap shell from the nest.

In Figure 20 the die structure at the next station is disclosed. In this case it is unnecessary to provide the expanding fingers for the inner surface of the flange, because the curling die 58 merely imparts a beading to the metal which has already been started in the right direction. This die 68 has an annular curling groove 69 in its bottom face which has a substantially semi-circular bottom. It functions to inwardly turn the edge of the flange 'to a substantially semi-circular cross-sectional curve.

In Figure 21, an apparatus for appropriately shaping or outwardly bending the lug forming portions 3| of the bead 39 is shown. This apparatus comprises a nest 5| which receives the blank, as previously described. Secured to the cross-head 54 is a depending sleeve having a laterally projecting flange Within a central bore in the sleeve there is mounted a rod 57, having a pad 59 on its lower end, and surrounded by a. spring 58, similar to the corresponding parts described above. Surrounding the central sleeve 10 is a second sleeve 12 of peculiar construction. At four spaced points around its inner periphery, this member is provided with elongated recesses 13, in each of which is mounted a pair of levers l4, l5, pivoted upon pin 16, extending into appropriate bores in sleeve 12. The outermost lever 14 is formed with a central longitudinal slot in which the other lever I5 is disposed for free pivoting movement with respect thereto. The lever 14 is normally held in retracted position by compression spring 'I'I disposed between its upper end and the supporting sleeve 12.

Each lever is provided with a cam surface adapted to be contacted by appropriate cam surfaces on the inner sleeve Hi. The surface 18 of each lever 14 is disposed so as to be engaged by the shoulder 19 just before the surface 80 of ,lever is engaged by the corresponding cam 8|.

The lower end of the outer lever is provided with a foot 82 having a concave arcuately curved surface 83 therein, and this foot extends downwardly adjacent the exterior surface of the cap skirt. The lever 75 is provided with an outwardly disposed foot 84 at its lower end having a cont-ex, arcuately curved surface which is positioned to engage the inner surface of the cap skirt adjacent the beaded edge.

A compression spring 85 surrounds the sleeve :2 and is disposed between a flange 86 thereon and the iiange ll of the inner sleeve 10. Surrounding all'of the parts, is a cylindrical casing 81 which may be appropriately mounted on the upper end of sleeve Ill.

When the assembly shown in Figure 21 descends, the movement of the sleeve 12 will be arrested by contact with the nest 5!, after the lower ends of levers 14, are on opposite sides of the cap skirt. Further downward movement of the cross-head and the inner sleeve 10, which is permitted by compression of spring 85, results in a camming action between the shoulder 19 and the upper end of lever 14, with the result that the foot 82 moves radially inwardly into supporting relation with respect to the outer surface of the cap skirt. The parts are now substantially in the position disclosed in Figure 21. Further downward movement of the sleeve 15] results in a camming action between surface 8| of the sleeve and surface 80 on each lever 15, with the result that each foot 84 is forced outwardly into contact with the cap skirt, either directly on the bead 30 or immediately therebelow. As the movement continues, spaced portions of the bead are outwardly bent, or otherwise shaped to correspond with the contacting surfaces on the levers. It will be noted that the outer lever constitutes a support for the cap skirt, and also presents a concave surface, into which the edge of the skirt is forced, thereby imparting a predetermined curve or'shapeto the wire.

When the cross-head is raised, lever 15 is withdrawn by engagement between its upper end 9| and surface 92 of the sleeve. The inwardly turned foot 82 of lever 14 is retracted by spring ll, so that it clears the outwardly bent portion of the wire edge. Thus the parts are free to be drawn upwardly from operative position, so that the biank may be moved to the next station.

In Figures 24. to 26, a die is disclosed which is adapted to perform the next step in the method, that is, to further curl the intermediate bead portions and inwardly turn the outwardly pressed lug forming portions. The cap blank, after this step has been performed, is shown in Figures 6, l4, and 15.

The bottom face of the die is provided with four circumferentially aligned grooves 92, each of which terminates at its ends in widened portions 93. The radial inner wall of each'groove at the portion 93 is formed into a smooth rounded shoulder 9 Adjacent each end of each groove, the die is provided with a cut-out portion 95 which is adapted to receive the lug forming portions of the cap skirt. Each groove has a substantially semi-circular bottom, as disclosed in Figure 26, and is adapted to impart a further curl to the undeformed bead portions of the edge of the cap skirt. Because of the presence of cut-cits 95, the curling action will not be continued entirely around the perimeter of the skirt. At the latter points, no positive curling action is imparted to the lug forming portions of the edge. However, the curling or rolling force impressed upon the intermediate bead portions by the grooves 92 will be transmitted through the shown in Figure 19 are used.

material of the cap skirt to the portions 3| thereof, which are received in the cut-outs, with the result that the latter portions will be drawn and bodily turned inwardly, without losing their predetermined shape, and will assume the position disclosed in Figures 24, 6 and 15. These portions 3| extend radially inwardly beyond the adjacent bead portions and form lugs, which, although in substantially completed form, may be bent upwardly and finished during the next step in the method, which is shown in Figure 27.

As pointed out above, the cut-out portions 95 of the die of Figure 24 perform no positive function, but merely permit the previously formed portions 3| of the cap skirt edge to swing inwardly, under the influence of the curling action imparted to adjacent edge portions by the grooves 92.

In the apparatus of Figure 27, expanding fingers 62' similar to the corresponding elements heads 65 project outwardly under the inturned lug forming portions 3|, and form an anvil surface which limits the inward axial bending imparted thereto by the die 55". The bottom face of the die is provided with a continuous curling surface 96 having a rounded corner. The corner or curve of the die surface is uniform around the entire circumference, and imparts a uniformly rounded lower external edge of the cap. Furthermore, it functions to impart a slight additional curl to the intermediate bead portions 30, and bends the lug forming portions 3| downwardly into contact with the members 65'.

Thus, the bottom edge of the cap skirt is ,uniformly rounded, and all points thereon are horizontally aligned, and lie in a common plane. The distance between the top of the cap and the thread engaging surface of each lug is accurately determined by the distance between the upper surface of the heads 65 and the bottom surface of the pad 59.

With the present method, it is necessary to position the blank in a particular angular adjustment with respect to the dies in only one step. When the cap is placed under the die of Figure 24, the outwardly bent lug forming portions 3| must be positioned under the cut-outs 95.

Although I have disclosed a specific means for imparting a predetermined shape to a lug forming portion of the beaded edge of a cap skirt, it should be distinctly understood that other means may be employed, and that the present invention is not limited to the apparatus shown and described herein, but must be given a scope consummate with .the accompanying claims and their equivalents.

I claim:

1. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises turning the free edge of the skirt inwardly around the entire perimeter of the skirt, bending eircumferentially spaced portions of the inwardly turned edge into predetermined shape, further inwardly turning the edge of the skirt entirely around the perimeter thereof except at said circumferentially spaced portions, and turning said circumferentially spaced, bent and shaped edge portions bodily inwardly to form locking lugs.

2. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the In this case, the

skirt inwardly to form at least a partial bead around the entire perimeter of the skirt, bending circumferentia'lly spaced portions of the partial bead into predetermined shape, further curling the partial bead entirely around the perimeter of the cap skirt except at said circumferentially spaced portions, and turning the bent and shaped partial bead portions bodily inwardly to form locking lugs.

3. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form at least a partial bead around the entire perimeter of the skirt, bending spaced portions of the partial bead into predeterminedshape, further curling the partial bead entirely around the perimeter of the cap skirt except at said spaced portions, and simultaneously turning the bent and shaped partial bead port-ions inwardly to form locking lugs.

4. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form at least a partial bead around the entire perimeter of the skirt, bending spaced portions of said bead outwardly into predetermined shape, further curling the bead of the skirt entirely around the perimeter thereof except at said spaced portions, and turning the spaced, outwardly bent and shaped bead portions inwardly to form locking lugs.

5. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form at least a partial bead around the entire perimeter of the skirt, bending circumferentially spaced portions of said partial bead outwardly into rounded, curved and predetermined shape, further curling the head of the skirt entirely around the perimeter thereof except at said circumferentially spaced portions, and turning the spaced rounded and curved bead portions inwardly to form locking lugs.

6. The method of making a lug type closure cap comprising the steps of forming a blank having a top and a substantially cylindrical skirt terminating in a substantially uniform lower edge, bending spaced portions of the cylindrical skirt at its uniform edge into a definite, predetermined shape, suitable for the thread engaging surface of a lug and different in shape from adjacent intermediate portions of the skirt edge, bodily displacing each of said bent and spaced portions from its original position into position to engage a thread on a receptacle and leaving the predetermined shape imparted to said spaced portions substantially unchanged by said bodily displacement.

'7. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge,

comprising bending spaced portions of the edge radially outwardly beyond the adjacent edge portions and into a definite, predetermined shape, suitable for the thread engaging surface of a lug, and bodily turning each of said portions inwardly from its outwardly bent position into position to engage a thread on a receptacle, without substantially disturbing its shape.

8. Themethod of making a lug type closure cap, comprising the steps of torming a blank having a top and a. substantially cylindrical skirt of uniform depth terminating in a continuous free edge, shaping spaced portions of the skirt at the continuous edge into a definite, predetermined contour, suitable for the thread engaging surface of a lug and different from the contour of adjacent intermediate portions of the skirt edge, bodily displacing each of said spaced portions from its original position. into a position inside of the cylindrical skirt portion to engage a thread on a receptacle and maintaining the predetermined contour imparted to said spaced portions substantially unchanged during and after the bodily displacement into said last-named position.

9. The method of making a lug type closure cap from a blank having a top and a substaniially cylindrical skirt terminating in a free edge, comprising bending spaced portions of the edge radially outwardly beyond the adjacent edge portions and into a definite, predetermined. arcuate curve, suitable for the thread engaging sur face of a lug, and bodily turning each of said portions inwardly from its outwardly bent position into position to engage a thread on a receptacle, without substantially disturbing its predetermined arcuate curve.

10. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, comprising curling the free edge of the skirt inwardly to form at least a partial bead around the entire perimeter of the skirt, outwardly bending spaced portions of the partial bead into a definite, predetermined arcuate curve, suitable for the thread engaging surface of a lug, further curling the partial bead of the skirt entirely around the perimeter thereof except at said spaced portions, and bodily turning each of said outwardly bent portions inwardly from its original position into position to engage a thread on a receptacle, without substantially disturbing its predetermined arcuate curve.

11. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a ice-e edge, comprising curling the free edge of the skirt inwardly to form at least a partial bead around the entire perimeter of the skirt, outwardly bending spaced portions of the partial bead into a definite, predetermined arcuate curve, suitable for the thread engaging surface of a lug, further curling the partial head of the skirt entirely around the perimeter thereof except at said spaced portions, bodily turning each of said outwardly bent portions inwardly from its original position into position to engage a thread on a receptacle, without substantially disturbing its predetermined arcuat'e curve, and finally imparting a slight additional curl to said edge and an additional upwardly directed bend to said portions, to give said skirt a uniform lower external edge.

12. The method of making a lug type closure cap from a blank-having a top and a skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stiifened, wire edge around the entire perimeter of the skirt, said reinforce serving to maintain said edge in any shape to which it is bent, bending said wired edge outwardly at spaced portions around said skirt, then further curling the free edge of the skirt inwardly intermediate said portions, and turn- 'ing said spaced portions into the interior of the cap skirt in position to form locking lugs without impairing the shape previously imparted thereto.

13. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stiffened, wire edge around the entire perimeter of the skirt, whereby said edge will maintain any shape to which it is bent, bending said wire edge and the cap skirt adjacent thereto outwardly at spaced portions around the skirt and'imparting to said outwardy bent portions a predetermined contour suitable for lugs, then further curling the edge of the skirt inwardly intermediate said portions, and turning said spaced portions into the interior of the cap skirt in position to form locking lugs withoutimpairing the shape previously imparted thereto.

14. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stifiened, wire edge around the entire perimeter of the skirt, bending said wire edge outwardly at spaced portions around said skirt and imparting to said outwardly bent portions a predetermined contour suitable for lugs, then further curling the edge of the skirt inwardly intermediate said portions, and turning said spaced portions into the interior of the cap in position to form locking lugs without impairing the shape previously imparted thereto.

15. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free. edge of the skirt inwardly to form a reinforced, stiffened, wire edge around the entire perimeter of the skirt, bending said wire edge outwardly at spaced portions around said skirt and imparting to said outwardly bent portions a predetermined arcuately curved contour suitable for lugs, then further curling the edge of the skirt inwardly intermediate said portions, and turning said spaced portions into the interior of the cap in position to form locking lugs without impairing the: shape previously imparted thereto.

16. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stiffened, Wire edge around the entire perimeter of the skirt, bending said wire edge outwardly at spaced portions around said skirt and imparting to-said outwardly bent portions a predetermined contour suitable for lugs, then further curling the edge of the skirt inwardly intermediate said portions, and simultaneously turning said spaced portions into the interior of the cap in position to form locking lugs without impairing the shape previously imparted thereto.

17. The method of making a, lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stiffened, Wire edge around the entire perimeter of the skirt, bending said wire edge outwardly at spaced portions around said skirt and imparting to said out wardly bent portions a predetermined contour suitable for lugs, then further curling the edge of the skirt inwardly intermediate said portions, and thereby drawing said spaced portions into the interior of the cap in position to form locking lugs without impairing the shape previously imparted thereto.

18. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stiffened, wire edge around the entire perimeter of the skirt, bending said wire edge outwardly at spaced portions around said skirt and imparting to said outwardly bent portions a predetermined contour suitable for lugs, then further curling the edge of the skirt inwardly intermediatesaid portions, and turning said spaced portions into the interior of the cap in position to "form locking lugs without impairing the shape previously imparted thereto or further curling said portions.

19. The method of making a lug type closure cap from a blank having a top and a substantially cylindrical skirt terminating in a free edge, which comprises curling the free edge of the skirt inwardly to form a reinforced, stiffened, Wire edge around the entire perimeter of the skirt, bending said wire edge outwardly at spaced portions around said skirt and imparting to said outwardly bent portions a predetermined contour suitable for lugs, then further curling the edge of the skirt inwardly intermediate said portions,

and turning said spaced portions into the intcrior of the cap in position to form locking lugs without impairing the shape previously imparted thereto or further curling said portions, and finally finishing the skirt by horizontally aligning all points on the lower edge thereof.

EDWARD M. ENKUR. 

